Technology roadmaps for superconductor electronics (SCE) and quantum computing are under development within the framework of the International Roadmap for Devices and Systems (IRDS). Advanced fabrication processes are needed to allow SCE to achieve its potential. The most complex digital superconductor electronic circuit made to date has only a little over one million Josephson junctions, the switching elements at the heart of most SCE logic. Much larger circuit complexities are required to meet the demands of applications such as quantum computing support, machine learning, or large-scale digital computing. Key fabrication needs include materials with processing temperatures compatible with CMOS back end of line (BEOL), superconductor materials with higher critical temperatures, capacitors, smaller dimensions, more wiring layers, and junctions that are scalable to smaller dimensions or have different behaviors. Work towards development of a suitable fabrication stackup is presented with a focus on areas of greatest need.